基于3D离散元的岩质边坡最大开挖角确定

Determination of largest excavation angle of rock slope based on 3D discrete element method

为解决岩质边坡最大开挖角确定的问题,利用3D离散元软件模拟边坡渐进开挖过程,探讨岩质边坡失稳的动态过程,从而确定岩质边坡的最大开挖角。以某水电坝址岩质边坡为例,对其进行数值模拟,结果所确定的最大边坡开挖角为47°。数值分析表明,将47°作为无支护条件下的边坡开挖角是合理的,与运动学方法所确定的38°开挖角相比,更接近实际的极限情况。故用3D离散元确定节理岩质边坡的最大开挖角具有一定的实际应用价值,对边坡分级开挖,确定合理边坡开挖角具有一定的指导意义。

To determine the largest excavation angle of rock slope,the failure of dynamics progress of rock slope is discussed by the simulation of gradual excavation based on 3D discrete element method,so as to determine its largest excavation angle.The numerical modeling is conducted with the case of a rock slope at the dam site of a hydropower project.The results show that the largest excavation angle is 47°;without the supporting condition,the slope would be safe with the excavation angle of 47°;Comparing with 38° that was determined by the traditional kinematic method,it is closer to the actual limits.Therefore,the largest excavation angle of rock slope determined by 3D discrete element method has practical value to determining a reasonable slope excavation angle when conducting the gradual excavation of slopes.